The invention relates to a micromechanically produced nozzle for producing reproducibly small drops.
In many devices and applications, liquids have to be dispensed in small and controlled quantities. For this purpose dispensing the liquid in droplet form is suitable. To do this, a suitable liquid reservoir is needed, as are a suitable mechanism for transporting the liquid and a suitable mechanism for producing a drop.
The object of the present invention is to develop a device for producing reproducibly small drops with diameters up to one micrometer.
This object is achieved by a device having a layered silicon structure with a through opening, a silicon oxide layer on the walls of the through opening, a portion of the silicon oxide layer being free-standing and forming a geometrically accurately defined nozzle opening. The decisive advantage of the present invention resides in the use of micromechanical fabrication methods, which permits the production of mechanical structures with submicrometer-accurate precision. In addition, by suitable selection of coating technologies, the surfaces are treated in such a way that the liquids are repelled or attracted by the surface. The present invention permits the production of reproducible, individual drops of diameters up to one micrometer in one exemplary embodiment. In a further exemplary embodiment, the invention permits the production of a mist of a number of small drops of equal size of up to one micrometer diameter. In a further exemplary embodiment, the nozzle opening can be reduced to a diameter of one micrometer by subsequent deposition of silicon oxide on the nozzle structure.